Thread: Adaptor shaft

Originally Posted by steveG

So you figured out the end float control Damien?

Steve

Yep, all in the machining.

Originally Posted by Vern

Spoke with barry today in regards to making this shaft, just need to get him the bits and some measurements.

we discussed what they would be made out of, suggested en26.
Told him my shaft was made from en26, discussed heat treating it, he said it should never have been heat treated! So who ever talked sheldon into getting this done, you ruined my holiday!😜.

He will use hy tuff.

Where did you get the EN26 info from? Sheldon's posts on here said it was made from 4140.

AISI 4140 Alloy Steel (UNS G41400)

I am sure it was Bush65 who suggested it be hardened. Likewise I am sure Barry was not suggesting you use a shaft made from annealed steel. Steel is often supplied in various hardness states. The outcast shaft has clearly been though a hardening process.

It says he used en26 in his thread, and i dicussed it with him today. The mob that did his machining he thinks used 4130 for the last batch.

From our discussion today, Sheldon did say those shafts were machined from a big block of en26 which doesn't get the full heat treatment in the centre due to size so they were treated again. Or something like that

Just went back and read the thread: My bolding on the relevant bits

Originally Posted by Lotz-A-Landies

The shaft won't be heat treated?

Is this O.K. for durability?

Some friends had adapter shafts to mate New Process manual boxes behind Ford V8's to Land Rover transfer boxes and while the untreated shafts worked for a while they did break in less time than some were happy with.

Originally Posted by the_grubb

Durability as in strength or wear?

Don't believe strength is going to be an issue here. Unlike axle halfshafts your not getting any torque multiplication when in low range. Hence I believe the material strength is sufficient - which I meant to be 4140 (not 4130 as I miss typed...)

Can see some benefit in wear reduction by flame hardening to Rc 50 from Rc30.

How about I get them hardened and provide a warranty - if you break it I replace it? Uh oh sounds like a challenge to me.... Obvisouly price will go up.



Material? Design? Dimensions? Stress raisers? Internal spline to NP box or flange mount? Alignment? Tolerances? Surface finish? LT230 transfer case or series? May not necessarily be that the breakage occured due to un(heat)treated shafts.

Originally Posted by Bush65

4140 is normally supplied in the hardened and tempered condition.

However, with heat treatment of large section there is some reduction in strength from the outside to the core (because the core can't be quenched at the same rate).
If you are starting with large diameter to suit the Isuzu flange OD, there will be some reduction where it is machined down to the 10 spline section.

It should be ok, but a hardness check will tell all.

Originally Posted by Dougal

The output flanges appear to be the same. My conversion has removed the output flange and gone from the gearbox spline to the transfer input spline.

I don't believe your shafts will stand up if not hardened. I forget the exact hardness mine was done to, but I was looking for a material with at least 1000 MPa yeild, the concern being stress concentration causing fatigue at the start of the splines.

The final material I received had a yeild when hardened of almost 2000MPa. Overkill, but it boasted minimal distortion in heat-treatment and the cost difference was minimal.
I received quotes from $NZ350-750 to make my shaft, in the end the workshop that started didn't finish it, I had to do the final machining and heat-treatment. Total cost around $NZ600.

I'll see if I can dig up my original calculations, but the FEA study I ran at the time shows 650 MPa bulk stress with 1450MPa max stress concentration at the start of the splines. The computer simulations tend to exaggerate stress concentration as computer modelled geometry tends to have sharper transitions than actual manufacturered parts.
This is with 2000Nm applied to the shaft. 2000Nm was the shaft torque required to light up wheels on tarmac. It represents 345Nm applied by the engine in first gear or 666 Nm applied in second gear.

Originally Posted by the_grubb

Been having problems uploading progress pics.....

Shafts = EN26 Heat Treated

http://www.aulro.com/afvb/attachment...ox-lt230-3.jpg

Did Sheldon tell you if the shafts were machined from pre-hardened billet EN26? If so the problem may be exactly what John (Bush65) mentioned.

Yes he did. He also said the later ones he thinks were 4130, the company that did them went bust and he can't be certain, did say he was sure they weren't en26.
Once I have done the measurements I need ben I will send it to you

Originally Posted by Vern

Yes he did. He also said the later ones he thinks were 4130, the company that did them went bust and he can't be certain, did say he was sure they weren't en26.
Once I have done the measurements I need ben I will send it to you

if they went bust, they could have and were probably made out of what ever crap they had on the rack.

I did think that dean